Good 955k when cold, hydraulics work and are basically quiet. After working 20 minutes or so, start to whine with a full bucket. Loses some speed lifting next. Fresh aw32 fluid, cleaned the big canister filter in the hydraulic tank. Same as before. Thinking of replacing the pump, wondering if there is anything else to check also, machine is very helpful with cool fluid. Any help appreciated, thanks.
Please post a Serial Number. A test procedure may be forthcoming provided you have a pressure gauge or gauges.
I assume you are talking about the main pump for the loader and not the transmission pump... Is the oil getting hot? That would be suggesting that your pump is worn and bypassing internally. I'm assuming that the pump is a gear or vane pump. The simplest way to check this out is to pull the pump and get it to a hydraulics shop that has a test bench. They can check it for internal bypassing (which is where the oil heating will be coming from) If it is bypassing, you can sometimes get a bit more life by tightening up some of the internal clearances by honing and/or changing some of the worn parts; otherwise, its a new pump. Hope this helps. Jon.
85J4302 looks like
There isn't really a test procedure as such. The main relief valve for the implement system is set to lift at 2350 ± 25 psi. You'll need a gauge that goes to at least 3000psi and tap it into somewhere handy after the pump. I would test it cold first, then keep the gauge on the system and run the machine until it gets warm and watch what happens to the relief pressure.
Maybe HEF member @pittsburgh cat man can give you some suggestions regarding where to hook up a pressure gauge.
If you drop the panel below the hyd tank the elbow with the high pressure line on it should have a plug where you can put a stor fitting in.
Thank you both for the replies, this machine has 9000 hours showing on the meter, someone took good care of it and it works fine. I don’t know if they came with oil coolers for the hydraulic system or not. The number looks like 85J4302.
Now I see the reply from Pittsburgh cat man, I will look for that fitting next. I just worked on my ford 3000 hydraulic pump that is easy to rebuild and the kit was cheap. I would look for a kit for the cat pump if I could figure out the name or number that applies. Thanks again.
cat number for pump is 7j0607
Post a photo of the plate and let’s all have a look.
Vickers vane pump, open it up and check the the vanes & vane surface. Maybe need cartridge. You can use 10W motor oil in that system.
I believe its Diesel motor oil. That's what one old Cat serviceman used to tell me. I'm not sure on the specs. I would use it sometimes when there was a good sale at F&F. I think it is mentioned that way in one of my manuals.
You would likely find that a 10W hydraulic oil might be cheaper than a motor oil containing all sorts of soot and sludge dispersant additives that a hydraulic system doesn't need. Remember that the 955K was built in a generation where manufacturers were full of the "one size fits all" mantra when it came to oils. 50 years later thinking has changed. It's a hydraulic system, use a hydraulic oil in it.
Yep, oil used to be called series 3, then changed to TO2 and so on. Nick
I couldn’t find a rebuild kit for the hydraulic pump, possibly because I tried finding one over the weekend. So I bought a replacement online, I hope to have it in hand before I try to remove the old pump, that way maybe I will remember where the bolts etc. go and can get it back together faster. I put aw32 oil in it because it was supposed to be 10w hydraulic oil, but a friend who has operated a D6d for years, sometimes commercialy, always uses non detergent motor oil from the farm store that comes in 2.5 gallon jugs, and is 30 weight, and it works fine In the hydraulic tank for him. I was afraid to try that in this machine because I don’t know what is correct for a D6d. I plan on sticking with aw32 unless I learn something better. Thanks everyone who responded, this forum has been very helpful.
A good plan of attack. Don't you have at least a maintenance manual.? Search the web for SEBU6520 but don't pay too much for one. A new copy is only $30 to download.
Diesel for hydraulic fluid in a 977, highly doubt. Adding some in cold temps. maybe but that may have been an old recommendation for the engine oil to make them easier to start when cold. Vickers vane pump should work fine with 10W/AW32 oil. Old excavators with multiple Vickers vane pumps ran 10W oil.
I lost a bucket tooth, am looking for a source to replace it, has a half moon cutout on the top and bottom. I hope someone here knows what to call it. I have not seen one like this on the web. Thanks for any help.
Photo.?
I believe he was referring to engine oil used in diesel engines like a SAE30 or 15/40. I have used diesel fuel for engine oil though to clean inside of an engine though. Not sure about today's ULSD though since there is such a lack of lubricity. Would fill an engine up with fuel and run for a few minutes and then drain and replace with correct oil.
The topic of discussion was hydraulic fluid.
There are two different options for teeth, short & long. See the attachment which is for short teeth. The only difference between the two is that for a long tooth the Tip Part Number changes from 5K-2925 to 4K-0034.
10W diesel engine oil. What I had heard was "the specs for diesel engines were more difficult to meet". As Nige said "times have changed". As difficult as it can be at times I would like to change with the times also. Another aside, there was an old mill at the shop. The stated oil change was to drain and fill with kerosene and run unloaded changing through the various gears for a certain amount of time. Drain and fill with clean oil. That was a long time ago. Cheers Shawn